160 research outputs found
Análise estática dos elementos de suspensão de um monopólio do tipo de formato eletrônico
Nowadays, it is essential that the suspension elements of the emulation cars have the capacity to withstand a great amount of effort to which they will be submitted and have an optimal per-formance for competitions, being indispensable that the material used meets physical require-ments and / or resistant mechanical properties. Method: In the first instance, an electric formula type car was designed, being manufactured with university-level engineering studies such as: finite element analysis, redesign and solutions to problems; to give validation of the elements of suspension that can be used in competition, where the evaluation and optimization of the parts of the car are important for its performance, such as the suspension to which a finite element analysis process was carried out in ANSYS used to perfect the vehicle, hoping to give it a stable control by reducing its weight, validating the resistance of the material and the piece designed. It showed a technological breakthrough that proposes advances in engineering studies to feed the ambition of the automotive sector and design engineering, as seen in the big teams of formula 1 in creating suspension elements for their competition vehicles. This example of a single-seater fulfills the objectives of having a rocker as a solid lightweight structure and scissors as a vital element of connection between the frame and chassis, representing benefits to the automotive sector, with the ability of the material to withstand applied loads.En la actualidad es esencial que los elementos de suspensión de los autos de competencia so-porten una gran cantidad de esfuerzos, también que el material cumpla con los requerimientos físicos y mecánicos para tener un desempeño óptimo. Este documento muestra la aplicación de estudios ingenieriles de nivel universitario, tales como el análisis de elementos finitos, rediseño y soluciones a problemas, para validar los elementos de suspensión de un monoplaza utilizado en competencia. Se analizaron los balancines y las tijeras de la suspensión por elementos finitos usando el software ANSYS, para evaluar y optimizar su desempeño en el monoplaza, esperando darle un control estable, reducción del peso y validar su diseño. Este estudio busca un avance tecnológico desde la academia, aplicando métodos de elementos finitos (FEM) a problemas automotrices que puedan aplicarse posteriormente en la industria, como se ve en las grandes escuderías de la fórmula 1 durante el desarrollo de nuevos elementos para sus vehículos de competencia que posteriormente se usan en los vehículos de calle. Esta metodología para el de-sarrollo de nuevos componentes demostró ser segura y eficiente ya que los diseños generados se pusieron a prueba en el monoplaza generando un excelente desempeño.Atualmente, é essencial que os elementos de suspensão dos carros de emulação tenham a capacidade de suportar uma grande quantidade de esforço ao qual serão submetidos e tenham um ótimo desempenho para competições, sendo indispensável que o material usado atenda aos requisitos físicos e / ou ou propriedades mecânicas resistentes. Método: Na primeira estadia, um carro tipo fórmula elétrica foi projetado, sendo fabricado com estudos de engenharia de nível universitário, tais como: análise de elementos finitos, redesenho e soluções para problemas; para dar a validação dos elementos de suspensão que podem ser usados na competição. Onde a avaliação e otimização das partes do monoposto são importantes para o seu desempenho, como a suspensão para a qual um processo de análise de elementos finitos foi realizado no ANSYS usado para aperfeiçoar o veículo, na esperança de dar a ele um controle estável re-duzindo seu peso, validando a resistência do material e da peça projetada. Mostrou um avanço tecnológico que propõe avanços em estudos de engenharia para alimentar a ambição do setor automotivo e de engenharia em desenho, como visto nas grandes equipes da fórmula 1 na criação de elementos de suspensões para seus veículos de competição. Este exemplo de um monoposto cumpre os objetivos de ter um balancim como uma estrutura sólida, de fôrma leve e umas tesouras como um elemento vital de conexão entre o chassi e o montante de cubo de roda, representando benefícios para o setor automotivo, tendo a capacidade que o material re-siste antes das cargas aplicadas
Upper Miocene deposits at the southern margin of the Guadalquivir Foreland Basin (central Betic Cordillera, S. Spain). Implications for the closure timing of the Atlantic-Mediterranean connections
Acknowledgments
We acknowledge the comments and suggestions made by two re- viewers, which have improved the quality of the paper. We thank Jodi Eckart for her help correcting the English text. Dr Sánchez-Almazo helped with the SEM analyses and photographs of foraminifers. This paper has been supported by the research project PGC2018–099391-B- 100 of the Spanish Ministerio de Ciencia, Innovación y Competitividad, and the research group RMN190 of the Junta de Andalucía.Mixed siliciclastic-carbonate deposits accumulated in several satellite sub-basins at the southern margin of the Guadalquivir Basin, the foreland basin of the Betic Cordillera (S. Spain). The prevailing coarse-grained sediments and deposition in shallow-water settings make it difficult to establish the precise age of the complete successions. For this reason, in previous studies, these deposits were attributed to the late Tortonian, although a Messinian age was not totally ruled out. The age of the upper Miocene deposits in the central part of the Guadalquivir Basin is here re-evaluated based on the analysis of several sections distributed in different areas: Antequera, Iznájar-Cuevas de San Marcos, Teba, and Bobadilla Estación. According to planktonic foraminifer and nannoplankton assemblages, the marine sedimentary infill of this sector of the southern margin of the Guadalquivir Basin is late Tortonian-early Messinian (late Miocene) in age. The occurrence of marine deposits characterized by the dominance of Globorotalia miotumida group, dextrally-coiled G. scitula, and the presence of G. margaritae, Globigerina multiloba, Discoaster quinqueramus, Amaurolithus primus, A. amplificus, and Reticulofenestra rotaria at the northern end of the Guadalhorce Corridor, the last active gateway in the Betic Cordillera connecting the Atlantic and the Mediterranean, indicates that it remained open until the early Messinian.Research project PGC2018–099391-B- 100 of the Spanish Ministerio de Ciencia, Innovación y CompetitividadResearch group RMN190 of the Junta de Andalucí
Evaluation of Fattening Efficiency of Grazing Bulls through Panel Data Envelop Analysis
The purpose of this paper was to assess fattening efficiency changes in grazing bulls, using panel data envelop analysis in two periods of time. The panel data were compiled by DEAP 2.1, which included the results of a 3-year period from 38 private farms (beef farms) in cooperatives of credits and services. The farms were on prairie savannahs, located on 21.4831 latitude, and -77.3174 longitude, less than 300 meters above sea level, province of Camagüey, mideastern Cuba. The output variable was total sold kg (TSKG), and the input variables were cost of Norgold (CN), fuel kg per ha (FKGXHA), fuel kg per livestock unit (FKGXLU), and unit of human labor force (UHL), which were highly correlated to the output variable. Table 2 shows that technical efficiency (TE), pure efficiency (PEC), and scale sufficiency (SEC), underwent 0.2%, 0.4, and 0.5%, respectively, by the third year of fattening. Technological change (TC) between the second and third years rose to almost 14%, and the total productivity factor (TPF) spiked as farmers became more skilled and experienced, with a 4.9% increase in comparison to the first year, and 13.7% in the second year
Alternative Eco-Friendly Methods in the Control of Post-Harvest Decay of Tropical and Subtropical Fruits
The effectiveness on several fruits by the application of alternative methods against fungi is summarized in the present chapter. Several investigations have reported the efficacy of these technologies for controlling fungal infections. Currently, high post-harvest loses have been reported due to several factors such as inefficient management, lack of training for farmers, and problems with appropriate conditions for storage of fruits and vegetables. Even now, in many countries, post-harvest disease control is led by the application of chemical fungicides. However, in this time, awareness about fungi resistance, environmental, and health issues has led to the research of eco-friendly and effective alternatives for disease management. The pathogen establishment on fruits can be affected by the application of GRAS compounds like chitosan, essential oils, salts, among others; besides, their efficacy can be enhanced by their combination with other technologies like ultrasound. Thus, the applications of these alternatives are suitable approaches for post-harvest management of fruits
Abrasive Wear Behavior of Al–4Cu–1.5Mg–WC Composites Synthesized through Powder Metallurgy
Different Al–4Cu–1.5Mg/WC composites were synthesized through powder metallurgy to establish the effect of WC particle addition on the abrasive wear behavior of an Al–4Cu–1.5Mg (wt. %) alloy. The wear tests were performed using a pin-on-disc tribometer at room temperature in dry conditions using SiC abrasive sandpaper as a counterbody and tribometer of linear configuration. The results showed that WC additions increase the hardness of the Al–4Cu–1.5Mg alloy due to the strengthening effect of particle dispersion in the aluminum matrix, which generates an improvement in the wear resistance of the composites by preventing direct contact of the sample with the counterbody, in turn delaying the plastic deformation phenomena responsible for the degradation sequence. In addition, the dominant wear mechanism was abrasive wear, and the increased friction coefficient did not bring a rapid wear rate, which was related to the enhanced deformation resistance due to the high hardness
El estado de conservación de los anfibios en el mundo
La declinación en las poblaciones de anfibios a nivel mundial es un fenómeno que se ha reportado, y tomado fuerza, a partir de la década de 1980. Actualmente se conocen 7888 especies de anfibios: 6958 anuros, 722 caudados y 208 gimnofiones (Frost, 2018). Las últimas cifras de la Lista Roja de especies amenazadas provistas por la Unión Internacional para la Conservación de la Naturaleza (UICN) muestran que, de las más de 6000 especies de anfibios evaluadas hasta ahora, 2100 se consideran amenazadas, lo que implica casi un tercio de la diversidad global de anfibios conocida y casi equivalente al porcentaje de especies amenazadas de aves y mamíferos en forma combinada (http://www.amphibians.org/whyamphibians/). Esta situación es más preocupante aún si consideramos que para una gran cantidad de especies de anfibios carecemos por completo de información como para determinar su situación real.Asociación Herpetológica Argentin
El estado de conservación de los anfibios en el mundo
La declinación en las poblaciones de anfibios a nivel mundial es un fenómeno que se ha reportado, y tomado fuerza, a partir de la década de 1980. Actualmente se conocen 7888 especies de anfibios: 6958 anuros, 722 caudados y 208 gimnofiones (Frost, 2018). Las últimas cifras de la Lista Roja de especies amenazadas provistas por la Unión Internacional para la Conservación de la Naturaleza (UICN) muestran que, de las más de 6000 especies de anfibios evaluadas hasta ahora, 2100 se consideran amenazadas, lo que implica casi un tercio de la diversidad global de anfibios conocida y casi equivalente al porcentaje de especies amenazadas de aves y mamíferos en forma combinada (http://www.amphibians.org/whyamphibians/). Esta situación es más preocupante aún si consideramos que para una gran cantidad de especies de anfibios carecemos por completo de información como para determinar su situación real.Asociación Herpetológica Argentin
Graph based study of allergen cross-reactivity of plant lipid transfer proteins (LTPs) using microarray in a multicenter study.
The study of cross-reactivity in allergy is key to both understanding. the allergic response of many patients and providing them with a rational treatment In the present study, protein microarrays and a co-sensitization graph approach were used in conjunction with an allergen microarray immunoassay. This enabled us to include a wide number of proteins and a large number of patients, and to study sensitization profiles among members of the LTP family. Fourteen LTPs from the most frequent plant food-induced allergies in the geographical area studied were printed into a microarray specifically designed for this research. 212 patients with fruit allergy and 117 food-tolerant pollen allergic subjects were recruited from seven regions of Spain with different pollen profiles, and their sera were tested with allergen microarray. This approach has proven itself to be a good tool to study cross-reactivity between members of LTP family, and could become a useful strategy to analyze other families of allergens
A genome-wide association study follow-up suggests a possible role for PPARG in systemic sclerosis susceptibility
Introduction:
A recent genome-wide association study (GWAS) comprising a French cohort of systemic sclerosis (SSc) reported several non-HLA single-nucleotide polymorphisms (SNPs) showing a nominal association in the discovery phase. We aimed to identify previously overlooked susceptibility variants by using a follow-up strategy.<p></p>
Methods:
Sixty-six non-HLA SNPs showing a P value <10-4 in the discovery phase of the French SSc GWAS were analyzed in the first step of this study, performing a meta-analysis that combined data from the two published SSc GWASs. A total of 2,921 SSc patients and 6,963 healthy controls were included in this first phase. Two SNPs, PPARG rs310746 and CHRNA9 rs6832151, were selected for genotyping in the replication cohort (1,068 SSc patients and 6,762 healthy controls) based on the results of the first step. Genotyping was performed by using TaqMan SNP genotyping assays.
Results:
We observed nominal associations for both PPARG rs310746 (PMH = 1.90 × 10-6, OR, 1.28) and CHRNA9 rs6832151 (PMH = 4.30 × 10-6, OR, 1.17) genetic variants with SSc in the first step of our study. In the replication phase, we observed a trend of association for PPARG rs310746 (P value = 0.066; OR, 1.17). The combined overall Mantel-Haenszel meta-analysis of all the cohorts included in the present study revealed that PPARG rs310746 remained associated with SSc with a nominal non-genome-wide significant P value (PMH = 5.00 × 10-7; OR, 1.25). No evidence of association was observed for CHRNA9 rs6832151 either in the replication phase or in the overall pooled analysis.<p></p>
Conclusion:
Our results suggest a role of PPARG gene in the development of SSc
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